Runway for airports and the like and method of making same



June 13, 1944. G, C, |TT| E'F|E| D 2,351,273

RUNWAY FOR AIRPORTS, AND THE LIKE, AND METHOD oF MAKING SAME Filed Nov. 14. 1942 INVENTOR. GLEN/v C- LITTLEF/sm ATToR/vfys Patented June 13, 1944 vEUNWAY Fon, AIRPORTS AND THE LIKE AND METHoD F MAKING SAME AGlenn C. Littlefield; Monterey, Calif., assigner of one-half to Mary I-I. Littlefield and one-half to JoseplipRMayo, .both of Monterey, Calif.

ApplicationNovember 14, 1942, Serial No. 465,582

8 Claims.

^ lThis Ainvention relates to'an improved runway 'for an air port or airplane landingV field, and has-for one vof its objects a method of making a turf-covered runway or landing field that pro'- vides a relatively smooth, slightly cushioned landing surface that is durable, substantially impervious to detrimental erosion, softening or other impairment due to rain, melting snow, artificial sprinkling, etc., and whicheld when completed will'blend with the surrounding green of grass or vegetation or which surrounding area may be readily made to blend with the runway or landing -fleld to camouflage the latter without diiculty or prohibitive cost.

Another objeci-l is a solid, turf-covered runway or landing eld, or the like, that is substantially impervious to erosion and softening by rain, melting snow or artificial sprinkling.

" Other objects and advantages will appear in the annexed specification.

They invention hereinafter described morel in detail,-contemplates the use of a binder grass that propagates from runners and which will establish a thick, heavy turf. The preferred grass is Kikuyu grass (Penm'setum clandz'stinum), as

this grassk has been discovered to have thecharacter'istics that most successfully accomplishes the desired result of surviving and attaining a vigorous growth under the conditions encountered in the practice of this invention, and which grass satisfactorily resists the severe abuse to which it is subjected on a runway and will grow -in'climatic and soil conditions where other grasses' of a generally similar type will not. However, this invention is Anot restricted to the use of Kikuyu grass except where specificallyl dened in the claims, since other binder grasses such as St. Augustine (Stenotaphrum secundatuml), Bermuda or St. Lucie may be employed whereconditions are favorable to their growth. Kikuyu grass is more drought resistantyanda more rampantV grower thanv the others, requiring less water, and grows well on anyA kind 0f soil, even poor, impoverished, sti clay, or on heavy clay' loam, gravel clay, red loam, sandy soils; alluvial vlei, etc., although it thrives best onmoist'vlei soil. Y

Kikuyugrass `is a hardy, aggressive and perlsistent' grower, having creeping characteristics. The growth of a single cutting or plant may cover an area of severalsquare yards, and vcuttings Vplanted from say 6" to 4 feetv apartwill relatively'quickly cover the area between cutitingsl with a dense, tough, relatively soft turf. Littlev waterfis required and the grassr stays green all summer and winter wherev there is 4some water and where sub-freezing winter temperatures are not encountered. Y l

As Kikuyu'grass `propagates by cuttings rather than by seed, it may readily be controlled or restricted to 4desired areas, thus being most suitable for use where fields surrounding air ports or runways are devoted to agricultural purposes.

While Kikuyu grass, land the other binder grasses having creepingcharacteristics may form a good, tough turf on soil; it has been found that .a runway merely covered by such grasses, vwhile satisfactory during a.v dry season, are notv satisfactory in a Wet season inasmuch as the soil becomes Wet and soft, and the turf of runners and grass will not stand the landing weight of heavy airplanes. However; runways made in accordance with this invention are turf covered and solid underall conditions requiredfor the safe anddesired landing of heavy airplanes, and which runways are well drained,vfree fromdust, and mud; and may be blended in appearance into surrounding fields,rl A'lso'the runways of this invention will successfully resist the most severe wear and also will resistv the vtenziency to show tracksv thatwouldfindicate to hostile aerial 'observers in time vof warthe frequency of use of the runways. Furthermore,` in Vthe event of extremely severe use', the runways Will quickly restore themselves by natural growth'of thegrass to their original condition should such use cause a slight change vin the appearance or Acondition ofthe runways. f y 5 In the drawing, I f

Fig. 1 is asemi-diagrammatic, sectional frag'- mentaryview illustrating the initial step in forming a runway in accordance with this invention.v -r f Fig. A2 is a semi-diagrammatic, sectional view illustrating another step in the method.

Fig.r3 is a semi-diagrammatic,sectional view illustrating a further step inthe development of arunway. Y 7' 'Fig 4 is-a semidiagrarnmatic-,y sectional view illustrating a modiicatior'i'oftl'ie rmethod of Figs.

5mg. 5 is a fragmentary, reduced size'pn View of the uncovered base that may be' employed in tively coarse or in pieces, say from about 1 inch" to about 4 inches in thickness,n thus leavingY cracks sufficient to allow `the runnersto come to the surface where they expandby rnatural growth to cover the layer of, rock-fandform anew turf 5.

After the above are in rows arranged in exactly the same manner as vfora brick road. The turf may first be substantially well covered with a layer of sand as inlayer 4 of rock is" laidft ms,

be rolled in order to settle .thecrushe'd rock layer into the turf 3 that has covered the surface of the ground.

After the secondu turf is formed over the; layer 4, a second layer of crushed rock Ii, in which the rock particles are preferably;smaller in size than the rock of layer Illislad over turf'5,which layerv must notbe too thick to smother out the' grass,

and may be about twoinches inthickness with the rock particlesfromone inch inthickness to about three inches inr thickness. This vlayer 6 may bek rolled; in thesarne,l mannerV as layer II,

and successive layers of -rock may thereafter be laid on the previously formed turf. in the same mannerv as above described for .the first two layers. The final layer may be-,ofgi relatively fine rock and .graded tothe desired lei/el.

, By watering,A ,thel @grass will readily come through the various layersto forrn a solid turf on the uppermost flnallayer; and the layers of rock will form a solid, base asgwell as providingforexcellent drainage,V said` topturf being designated 1.

It is obvious, of course, that theuppermost turf may, if desired,v beGQvered with, another layer of crushed rock at any time subsequent to theformation ofthe upper layer or shouldunexpected settling of groundconditions or any unusual occurrence result in-a pocket .or-depressions, such depressions may l hereinbeforedescribedfwithout removal `of any portion of the previously laidf'layersrof rock. I In Figs. 4, 5 isillustrated an alternative form of making a substantially :solid runway, in which concrete III or cement or the like, is laidon previously prepared ground with suitable ,boards or forms being used to provide cracksbII f rom'the soil to the surface of the concrete after setting of the concrete and removal of the forms, Such cracksare preferably irregular` in plan vewv Fig. 5) so as to insure against long linesfof weakness and regularity in appearance during growth. Cuttings planted int cracksof from 6 to 1.2 inches apart will readily grow and spread out Aover the concrete surfaces f between cracks to provide a thick turf over the concrete and which contributes to binding the blocks of concrete in position if the latter are disconnected, although as shown in the lower portion of Fig.5, the concrete may be connected at various points, such as indicated at I I to form connections of concretebetween blocks thereof as well-asA providing adequate cracks for thegrass. i t 4., Y

These cracks, of course, areY preferably only from 6 to 36 inches apart so as'tobe inconsequential insofar astheir effect-onthetiresv of an airplane are concerned. 'Y A i v In both forms of. thehinventiomthe grass not only functions as a covering and camouiiage for vfi 11 edb y observing the steps Y dicated', before laying the bricks if desired, al-

, though in some instances the bricks may be laid directly on the'turf. The runners I4 then grow through cracks I5 and spread out over the top surfaces of the bricks to form a turf I6 over said bricks.

VTheuse of the descriptive terms runner forming binder grass in the claims includes any stoloniferous strain of grass, and the term rocklike material, covers such materials as brick, concrete, cement, and the like.

Having described-my invention, I claim:

1. The method of making a turf-covered runway, landing held, or the like, that comprises the steps: substantially leveling the ground soil of the desired area for such runway; planting a runner forming, binder grass in said leveled soil at a plurality of points distributed throughout said area and spaced from each other such distances as are within the capacityl of thegrass runners to cover .the soil in said area with turf; spreading a substantially uniform layer of rock particles over the turf covering said area after said turf is formed.; permitting the runners from said turf and grass to grow through said layer of rock andY thereover until a second turf is formed over` said layer whereby a double layer of Vturf is formedabove said ground with a uniform layer of'rocktherebetween. l Y I 2. The method of `making a turf-covered runway, landing field, o r the like, that comprises the steps: substantially leveling the ground soil ofthe desired area.y for such runwayyplantingga runner forming, binder grassin s aid leveled Vsoil at a plurality of points distributed throughout said area and spacedl from; each other such distances as are within the capacity ofthe grass runners to cover the soil in said arearvwith af relatively thick turf; spreading a substantially uniform layer of rock particles over the turf covering said Aarea after said turf informed; permitting the runners from said turf and grass to growfthrough said layer of rockland thereover until arsecond turf is formed over said layer ;-thereafter repeating the aforesaid steps of spreading roolcparticles over the turf and permitting the coverage thereof by turf produced fromfthe turfbelow such layer,

. runners to cover the soil in said area withV arela tively thick turf;` spreading a substantially uniform layer of rock particles overtheturf covering said areaaftersaidturf is formed and rolling said layer down against said turf so as to compact said layer and to force particles thereof between the runners of said turf to said soil; permitting runners from said turf to grow through interstices between particles of said layer to above the latter and to spread over said layer thereby forming a second turf above and over the latter.

4. The method of making a turf-covered runway, landing eld, or the like, that comprises the steps: substantially leveling the ground soil of the desired area for such runway; planting a runner forming, binder grass in said leveled soil at a plurality of points distributed throughout said area and spaced from each other such distances as are within the capacity of the grass runners to cover the soil in said area with a relatviely thick turf; spreading a substantially uniform layer of rock particles over the turf covering said area after said turf is formed and rolling said layer down against said turf so as to compact said layer and to force particles thereof into said turf; permitting runners from said turf to grow through interstices between particles of said layer to above the latter and to spread over said layer for forming a second turf covering the latter; spreading a second layer of rock particles of sizes smaller than the particles of the first mentioned layer over said second turf and rolling said second layer down against said second turf so as to compact said layer and to force particles thereof into said second turf; thereafter permitting runners from said turf to grow through interstices between particles of said layer to above the latter and to spread over said second layer for forming a third turf covering said second layer.

5. 'I'he method of making a turf covered run- Way, landing eld, or the like, that comprises the steps: substantially leveling the ground soil of the desired area for such runway; planting a runnner forming, binder grass in said leveled soil at a plurality of points distributed throughout said area and spaced from each other such distances as are Within the capacity of the grass runners to cover the soil in said area with a relatively thick turf; spreading a substantially uniform layer of rock particles of generally uniform size over the turf covering said area after said turf is formed and rolling said layer down against said turf; permitting runners from said turf to grow through interstices between particles of said layer to 'above and over the said layer until a second turf is formed over said layer; thereafter repeating the steps of spreading rock particles over the turf :v formed therebelow and over the preceding layer -in which each layer that is successively spread comprises finer particles of rock than the preceding layer whereby a plurality of turfs will be formed, each adjacent pair of which is separated by a layer of rock particles with the uppermost layer supporting the turf of the runway or landing field.

6. The method of covering a dirt runway or landing field with turf that comprises planting said runway with grass from one of the group: Kikuyu, St. Augustine, St. Lucie; and after the natural growth thereof forms a turf :covering the runway, spreading a series of layers of rock particles thereover at time intervals sufficient to permit the grass runners from the grass planted in the soil of the runway to form a turf over the rock particles of each layer.

7. A runway or landing field planted with a runner forming, binder grass and covered with a plurality of layers of crushed rock, and a turf from said binder grass disposed between each pair of adjacent layers of rock and over the uppermost of said layers; said turfs being connected by runners thereof with each other and with the rooted plants for maintaining growth in the turf covering the uppermost layer and for binding the rock particles of said layers together.

8. The method of making a turf covered runway, landing eld, or the like, that comprises the steps; substantially leveling the soil of the desired area for such runway; planting a stoloniferous strain of grass in said leveled soil at a plurality of points distributed throughout said area and spaced from each other at such distances as are within the capacity of runners from such grass to cover the soil in said area with a turf; covering said turf with spaced bodies of rock-like material, and thereafter permitting the runners of said grass to grow through the spaces between said bodies and to cover said bodies in interlacing relationship thereby forming a turf over said bodies.

GLENN C. LIT'ILEFJELD. 

